The collection of biologic samples is the first crucial step in a number of processes that utilize modern analytic techniques to identify sample source based on analyses of molecular components. These techniques may include genetic analyses to establish sample donor identity, for example.
A common use of DNA technology is the identification of individuals by the genetic profile of DNA present in the sample. Applications of such testing include forensic cases to match suspects with evidence, paternity testing to identify a child's father, missing persons identity, military “dog tag”, convicted felon DNA data bases, victim identification in mass fatalities, and historic and genealogic investigations. These applications, for the most part, utilize genomic DNA which is found in most cells of the body (except, notably, in red blood cells) and which contains paternal and maternal derived genomic content. The potential applications have in common that all require a reference sample for comparison. The comparison samples may be relatives, samples from the tested individual or samples in an available database. Large databases of typing information for DNA samples are maintained by the FBI in the US, and by police agencies abroad, and, in many cases, newly acquired data are compared to these. Use of this information for forensics necessitates that all techniques used are efficient and reproducible and the processes by which the data are obtained must stand up as evidence in criminal court cases.
In some instances when sufficient nuclear DNA is not present, and with certain sample types (bone, hair, nails, charred remains), identification may rely on the analysis of mitochondrial DNA (mtDNA). Maternally derived, mtDNA, therefore yields different and more limited information than nuclear DNA. While mtDNA may establish sample genealogic origins and data on population migrations, only identity to mother and siblings rather than a general identity profile can be established.
A common element in all of the analyses of biologic analytes from acquired samples is the need for sufficient quantity of the desired substance to do necessary testing and the need for the analyte to be in a state that is amenable to the analyses that are performed to derive useful information. For the most commonly used DNA analyses, there must be sufficient sample (in most cases at least 1 ng of DNA) and the material must be reasonably intact so that pertinent sequences have not been degraded and further must not contain any materials that would interfere with test processes to be performed. Further requirements, such as protection from contamination, may accrue for samples that are collected in advance of the extraction and analysis processes and stored prior to use.
In order to address the growing demand for DNA analysis, including forensic DNA fingerprinting and medical diagnoses and analyses, there is a critical need for improvements in collection and analysis techniques. The medical and forensic DNA communities would therefore greatly benefit from a DNA technology platform suitable for DNA collection and analysis that is highly reliable and accurate.